Conventionally, as an electrically operated braking apparatus, an art (refer to Japanese Patent No. 2000-283193 for an example) is utilized in which a brake torque or a pressing force by a caliper is directly detected by a sensor, and a fluctuation frequency of the detected torque or force is found and used to detect the occurrence of an abnormal vibration.
However, a particular sensor, i.e., a brake torque sensor or a load sensor, is necessary to detect the abnormal vibration in the above related art, which leads to not only higher costs, but also a more complicated configuration of the braking apparatus itself in order to accommodate such sensors.